Author

Date of Award

Document Type

Degree Name

Administrative Home Department

Department of Civil and Environmental Engineering

Advisor 1

Noel Urban

Advisor 2

Judith Perlinger

Committee Member 1

Ann Maclean

Committee Member 2

Gordon Paterson

Abstract

Mercury (Hg) pollution adversely affects ecosystems and human health. Mercury in the form of methylmercury (MeHg) bioaccumulates in aquatic ecosystems, thereby affecting fish, fish-eating wildlife and humans. The goal of this research was to clarify the effects of environmental factors on MeHg concentrations in fish in the inland lakes of the Upper Peninsula of Michigan. Of the 74 lakes for which data were available, 56 had fish mercury concentrations above the water quality guideline. Multivariate statistical analyses indicated different factors affect fish Hg concentrations in large and small lakes.

Polychlorinated biphenyl (PCB) compounds are a class of persistent, bioaccumulative and toxic organic pollutants. Atmospheric deposition has been considered to be the major input of PCBs to Lake Superior. The objective of this project was to identify the source of PCBs to Lake Superior fish. Positive Matrix Factorization (PMF) identified multiple factors that contribute to the observed distribution of congeners. The congener distributions in air and fish were different from each other. Comparison of congener distributions in fish and sediments showed significant similarity, suggesting that the sediments are a source of PCBs to the fish.